/**
 * Created by gongp on 2017/8/3.
 * x
*/
import com.jcraft.jsch.*;
import java.awt.*;
import javax.swing.*;
import java.io.*;

public class Sudo{
    public static void main(String[] arg){
        try{
            JSch jsch=new JSch();

            String host=null;
            if(arg.length>0){
                host=arg[0];
            }
            else{
                host=JOptionPane.showInputDialog("Enter username@hostname",
                        System.getProperty("user.name")+
                                "@localhost");
            }
            String user=host.substring(0, host.indexOf('@'));
            host=host.substring(host.indexOf('@')+1);

            Session session=jsch.getSession(user, host, 22);

            UserInfo ui=new MyUserInfo();
            session.setUserInfo(ui);
            session.connect();

            String command=JOptionPane.showInputDialog("Enter command, execed with sudo",
                    "printenv SUDO_USER");

            String sudo_pass=null;
            {
                JTextField passwordField=(JTextField)new JPasswordField(8);
                Object[] ob={passwordField};
                int result=
                        JOptionPane.showConfirmDialog(null,
                                ob,
                                "Enter password for sudo",
                                JOptionPane.OK_CANCEL_OPTION);
                if(result!=JOptionPane.OK_OPTION){
                    System.exit(-1);
                }
                sudo_pass=passwordField.getText();
            }

            Channel channel=session.openChannel("exec");

            // man sudo
            //   -S  The -S (stdin) option causes sudo to read the password from the
            //       standard input instead of the terminal device.
            //   -p  The -p (prompt) option allows you to override the default
            //       password prompt and use a custom one.
            ((ChannelExec)channel).setCommand("sudo -S -p '' "+command);


            InputStream in=channel.getInputStream();
            OutputStream out=channel.getOutputStream();
            ((ChannelExec)channel).setErrStream(System.err);

            channel.connect();

            out.write((sudo_pass+"\n").getBytes());
            out.flush();

            byte[] tmp=new byte[1024];
            while(true){
                while(in.available()>0){
                    int i=in.read(tmp, 0, 1024);
                    if(i<0)break;
                    System.out.print(new String(tmp, 0, i));
                }
                if(channel.isClosed()){
                    System.out.println("exit-status: "+channel.getExitStatus());
                    break;
                }
                try{Thread.sleep(1000);}catch(Exception ee){}
            }
            channel.disconnect();
            session.disconnect();
        }
        catch(Exception e){
            System.out.println(e);
        }
    }

    public static class MyUserInfo implements UserInfo, UIKeyboardInteractive{
        public String getPassword(){ return passwd; }
        public boolean promptYesNo(String str){
            Object[] options={ "yes", "no" };
            int foo=JOptionPane.showOptionDialog(null,
                    str,
                    "Warning",
                    JOptionPane.DEFAULT_OPTION,
                    JOptionPane.WARNING_MESSAGE,
                    null, options, options[0]);
            return foo==0;
        }

        String passwd;
        JTextField passwordField=(JTextField)new JPasswordField(20);

        public String getPassphrase(){ return null; }
        public boolean promptPassphrase(String message){ return true; }
        public boolean promptPassword(String message){
            Object[] ob={passwordField};
            int result=
                    JOptionPane.showConfirmDialog(null, ob, message,
                            JOptionPane.OK_CANCEL_OPTION);
            if(result==JOptionPane.OK_OPTION){
                passwd=passwordField.getText();
                return true;
            }
            else{
                return false;
            }
        }
        public void showMessage(String message){
            JOptionPane.showMessageDialog(null, message);
        }
        final GridBagConstraints gbc =
                new GridBagConstraints(0,0,1,1,1,1,
                        GridBagConstraints.NORTHWEST,
                        GridBagConstraints.NONE,
                        new Insets(0,0,0,0),0,0);
        private Container panel;
        public String[] promptKeyboardInteractive(String destination,
                                                  String name,
                                                  String instruction,
                                                  String[] prompt,
                                                  boolean[] echo){
            panel = new JPanel();
            panel.setLayout(new GridBagLayout());

            gbc.weightx = 1.0;
            gbc.gridwidth = GridBagConstraints.REMAINDER;
            gbc.gridx = 0;
            panel.add(new JLabel(instruction), gbc);
            gbc.gridy++;

            gbc.gridwidth = GridBagConstraints.RELATIVE;

            JTextField[] texts=new JTextField[prompt.length];
            for(int i=0; i<prompt.length; i++){
                gbc.fill = GridBagConstraints.NONE;
                gbc.gridx = 0;
                gbc.weightx = 1;
                panel.add(new JLabel(prompt[i]),gbc);

                gbc.gridx = 1;
                gbc.fill = GridBagConstraints.HORIZONTAL;
                gbc.weighty = 1;
                if(echo[i]){
                    texts[i]=new JTextField(20);
                }
                else{
                    texts[i]=new JPasswordField(20);
                }
                panel.add(texts[i], gbc);
                gbc.gridy++;
            }

            if(JOptionPane.showConfirmDialog(null, panel,
                    destination+": "+name,
                    JOptionPane.OK_CANCEL_OPTION,
                    JOptionPane.QUESTION_MESSAGE)
                    ==JOptionPane.OK_OPTION){
                String[] response=new String[prompt.length];
                for(int i=0; i<prompt.length; i++){
                    response[i]=texts[i].getText();
                }
                return response;
            }
            else{
                return null;  // cancel
            }
        }
    }
}